Chromium Chalcogenide based Thermoelectrics

铬硫族化物基热电材料

• 批准号: 338007693
• 负责人: Professor Dr. Wolfgang Bensch
• 金额: --
• 依托单位: Institut für Mikrosystemtechnik (IMTEK)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/338007693?language=en
• 关键词: Chromium; Chalcogenide; based; Thermoelectrics

For many commercial processes like combustion engines losses due to waste heat are inevitable. Thermoelectric materials mounted in a thermoelectric generator can partially recover the otherwise lost energy by converting the existent temperature gradient to an electrical voltage. However, current efficient thermoelectric materials consist of rare and hazardous elements like Lead, Antimony, Tellurium, etc.The project Chrome chalcogenide based Thermoelectrics investigates binary (CrxCrS2) and ternary (MCrS2 (M = Cu, Ag)) chrome chalcogenides as up until now unexplored thermoelectric materials. Besides the relative ease of accessibility of consisting elements, chrome chalcogenides are known semiconductors which can be highly doped. Hence, substitution of anions and cations is possible for a broad compositional range without alterations to the general structure. The influence of substitution on real structure and thermoelectric properties, especially Seebeck coefficient as well as electrical and thermal conductivity will be thoroughly investigated during this project.The electrical conductivity can be modified by changing the number of charge carriers and the width of the band gap. On the other hand, the Seebeck coefficient conceivably increases due to additional spin entropy. A decrease of the thermal conductivity can be achieved by substitution and topotactic reactions, introducing specific defect structures (point defects, planar defects and nanoprecipitates). To rationalize the chemical, micro- and nanostructural properties of these new thermoelectric materials challenging and partially novel to-be-developed Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) methods have to be used in order to investigate correlations between synthesis, composition, (micro)structure and thermoelectric properties. The combination of both methods allows a complete and quantitative model for complex materials on all relevant length scales. For the thermoelectric characterization, a new type of measurement set-up will be developed which enables quick and reliable determination of the characteristic variables for thermoelectric materials of numerous samples. Particularly promising materials will be investigated in detail by in and ex situ TEM and XRD heating experiments to investigate structural changes upon cyclic heating; these will be correlated to alterations of thermoelectric properties.Ultimately, this research project also addresses relevant application-technological topics like the preparation of low ohmic contacts for integration in chrome chalcogenide based thermoelectric generators. Therefore, appealing questions arise for basic research, upon answering; a significant benefit for the thermoelectric community can be expected, like long term stability of thermoelectric materials and the specific failure mechanism.

对于许多商业过程，如内燃机，由于废热造成的损失是不可避免的。安装在热电发电机中的热电材料可以通过将存在的温度梯度转换为电压来部分地恢复否则损失的能量。然而，目前有效的热电材料包括稀有和危险的元素，如铅，锑，碲等。该项目Chrome硫属化物基热电研究二元（CrxCrS2）和三元（MCrS2（M = Cu，Ag））Chrome硫属化物，直到现在尚未开发的热电材料。除了组成元素的可接近性相对容易之外，Chrome硫属化物是已知的可以高度掺杂的半导体。因此，阴离子和阳离子的取代对于宽的组成范围是可能的，而不改变一般结构。本项目将深入研究取代对真实的结构和热电性能的影响，特别是Seebeck系数以及电导率和热导率，电导率可以通过改变载流子的数量和带隙的宽度来改变。另一方面，由于额外的自旋熵，塞贝克系数可以想象地增加。热导率的降低可以通过取代和拓扑反应来实现，引入特定的缺陷结构（点缺陷、平面缺陷和纳米沉淀物）。为了合理化这些新热电材料的化学、微结构和纳米结构特性，必须使用具有挑战性和部分新颖的待开发的透射电子显微镜（TEM）和X射线衍射（XRD）方法，以研究合成、组成、（微）结构和热电特性之间的相关性。这两种方法的结合允许在所有相关长度尺度上对复杂材料进行完整的定量模型。对于热电特性，将开发一种新型的测量装置，能够快速可靠地确定许多样品的热电材料的特性变量。特别有前途的材料将详细调查和非原位TEM和XRD加热实验，以调查循环加热后的结构变化，这些将与热电性能的改变。最终，该研究项目还涉及相关的应用技术主题，如低欧姆接触的制备集成在Chrome硫族化合物为基础的热电发电机。因此，基础研究中出现了一些有吸引力的问题，在回答这些问题时，可以预期热电社区将获得重大利益，例如热电材料的长期稳定性和特定的失效机制。

项目成果

High‐Pressure Sintering of Rhombohedral Cr2S3 Using Titanium–Zirconium–Molybdenum Tools

• DOI: 10.1002/adem.201900430
• 发表时间: 2019-09
• 期刊: Advanced Engineering Materials
• 影响因子: 3.6
• 作者: D. Groeneveld;H. Groß;Anna‐Lena Hansen;T. Dankwort;Julian Hansen;J. Wöllenstein;W. Bensch;L. Kienle;J. König

Does Low‐Level Substitution Aid in Improving Thermoelectric Properties? A Case Study of M0.1Ni0.9Cr2S4 (M = Mn, In)

低水平取代有助于提高热电性能吗？

• DOI: 10.1002/adem.202100828
• 发表时间: 2021
• 期刊: Advanced Engineering Materials
• 影响因子: 3.6
• 作者: H. Groß;M. Poschmann;D. Groeneveld;J. D. König;L. KienleW. Bensch
• 通讯作者: L. KienleW. Bensch

Structural properties of the thermoelectric material CuCrS2 and of deintercalated CuxCrS2 on different length scales: X-ray diffraction, pair distribution function and transmission electron microscopy studies

• DOI: 10.1039/c7tc02983g
• 发表时间: 2017-09-28
• 期刊: JOURNAL OF MATERIALS CHEMISTRY C
• 影响因子: 6.4
• 作者: Hansen, Anna-Lena;Dankwort, Torben;Bensch, Wolfgang
• 通讯作者: Bensch, Wolfgang